A-A+
试将30H R7 B A PSW DPTR中的数据依次压入堆栈。并指出每次堆栈操作后 SP=
问题详情
试将30H、R7、B、A、PSW、DPTR中的数据依次压入堆栈。并指出每次堆栈操作后,SP=?、(SP)=?设原SP=60H,当前工作寄存器区为0区,(30H)=11H,R7=22H,B=33H,A=44H,PSW=55H,DPTR=6677H。
参考答案
PUSH 30H ;SP=61H, (SP)=(61H)=11H
PUSH 07H ;SP=62H, (SP)=(62H)=22H
PUSH B ;SP=63H, (SP)=(63H)=33H
PUSH Acc ;SP=64H, (SP)=(64H)=44H
PUSH PSW ;SP=65H, (SP)=(65H)=55H
PUSH DPH ;SP=66H, (SP)=(66H)=66H
PUSH DPL ;SP=67H, (SP)=(67H)=77H将R7中数据压入堆栈时,不能写成PUSH R7;而应写成PUSH 07H; 07H是当前工作寄存器区为0区时的R7直接地址。